Sulphur L 2,3 and L 1 XANES investigations of pyrite and marcasite

Abstract

S L 2,3 and L 1 XANES of the polymorph minerals pyrite (FeS 2) and marcasite (two different cleavage planes) were measured in total electron yield mode using synchrotron radiation. Small but distinct differences were found in the fine structure of these spectra. Calculations with the FEFF-8 code were performed to reproduce the experimental data. Ex situ UV–ozone oxidation of the samples reveals different reactivity. Sulphate was identified on the pyrite and one marcasite cleavage planes whereas the second plane normal to the first one oxidises with changing quanta of sulphate and sulphite.